Omitir los comandos de cinta
Saltar al contenido principal
SharePoint

Servicio Geológico Colombiano

Skip Navigation Linksv3ch15
Seleccione su búsqueda
miig

Sedimentitas marinas del Neógeno en la bahía de Tumaco, Nariño

 Volume 3 Chapter 15

Chapter 15

Isthmian Bedrock Geology: Tilted, Bent, and Broken

By Camilo MONTES and Natalia HOYOS

Pages 299–333

Manuscript accepted October 29, 2018


Abstract 


A review of the bedrock geology of the Isthmus of Panama highlights tectonic deformation—tilting, bending and breaking—, as major controlling factors in the sites and modes of Cenozoic sedimentation. Deformation in Paleocene – early Eocene times folded and faulted a basement complex composed of plateau basalts, pelagic and hemipelagic sequences, and an overprinted magmatic arc. This deformation episode brought parts of the Isthmus from lower bathyal depths to subaerial exposure, bringing about basement cooling and eroding the plutonic bodies that make up the roots of a Campanian to Eocene arc. A clastic–carbonate, less deformed, upper Eocene and younger sedimentary sequence onlaps non–conformably the basement complex. Southward tilting of the Isthmus controlled the accumulation of the clastic wedge, recording first shallow marine depositional environments, followed by deepening, and then by shoaling. This sequence resulted from basin tilting that simultaneously raised the San Blas range, eroding it, while deepening the axis of the Chucunaque Basin. Bending and breaking of the Isthmus took place as it was being detached from the trailing edge of the Caribbean Plate, and marked the start of left–lateral offset of the Isthmus in late Eocene times.

Keywords:   Panama, isthmus, deformation.